You are enjoying your breakfast after having put some salt on your scrambled eggs when your nerdy brother presents you with an ice cube floating in a glass of water and a short length of string. He challenges you to remove the ice cube from the glass using the string without tying any knots. What strategy do you use to remove the ice cube from the water glass?
Take the string and soak it in the water. Let the string rest across the ice cube. Reach across the table and get the salt that you used on your eggs; pour the salt over the string and the ice cube. The salt causes the ice to melt. However, when you stop pouring the salt, the water that formed on the top of the cube will refreeze with the string embedded in it. Now you can lift the ice cube with the string.
Today's brain teaser courtesy of Braingle.com.